It has any reason despite grow the number of lines of code?
Phoronix: Wayland Now Has A Nested Compositor Back-End
Wayland has received quite a number of new patches in the past month from a variety of different developers, including the ability to run Wayland off a Linux frame-buffer, but now this weekend it has picked up another interesting feature: the ability to run another Wayland compositor instance within itself. There's now patches out there for running a nested/session compositor of Wayland on top of an existing Wayland Display Server that in turn is running on a X11/DRM compositor and communicating with the hardware...
http://www.phoronix.com/vr.php?view=ODgzNA
It has any reason despite grow the number of lines of code?
X already has it in the form of Xnest, so I googled that, and their reasoning is "Xnest is a nested X server: a display that runs in a window within another display. It's useful for testing GUI applications as a different user, trying out several desktop environments at the same time, or getting screenshots of the login process."
Do you really think they would drop in code just to have more lines total?
Xnest has been effecitvely replaced with Zephyr.
It's a nice thing to have.
If Wayland truly did a nested server with 600 lines of code then that proves that Wayland's approach is massively simpler. People have been working on nested X Servers for years and they still don't have a lot of things right.